"An eye for an eye"? Neural correlates of retribution and forgiveness.

Brüne M, Juckel G, Enzi B - PLoS ONE (2013)

Bottom Line:
Neuroimaging studies suggest that punishing unfairness is associated with the activation of a neural network comprising the anterior cingulate cortex, anterior insula, the ventral striatum, and the dorsolateral prefrontal cortex (DLPFC).A substantial number of subjects did not retaliate.Neurally, this "forgiveness" behaviour was associated with the activation of the right (and to a lesser degree left) DLPFC, a region that serves as a cognitive control region and thus may be involved in inhibiting emotional responses against unfairness.

ABSTRACTHumans have evolved strong preferences for equity and fairness. Neuroimaging studies suggest that punishing unfairness is associated with the activation of a neural network comprising the anterior cingulate cortex, anterior insula, the ventral striatum, and the dorsolateral prefrontal cortex (DLPFC). Here, we report the neuronal correlates of retribution and "forgiveness" in a scenario, in which individuals first acted as a recipient in an Ultimatum Game, and subsequently assumed the position of a proposer in a Dictator Game played against the same opponents as in the Ultimatum Game. Most subjects responded in a tit-for-tat fashion, which was accompanied by activation of the ventral striatum, corroborating previous findings that punishing unfair behaviour has a rewarding connotation. Subjects distinguished between the human opponent and computer condition by activation of the ventromedial PFC in the human condition, indicative of mentalising. A substantial number of subjects did not retaliate. Neurally, this "forgiveness" behaviour was associated with the activation of the right (and to a lesser degree left) DLPFC, a region that serves as a cognitive control region and thus may be involved in inhibiting emotional responses against unfairness.

pone-0073519-g005: Contrast [ultimatum game: ‘positive effect of all conditions’] and signal changes derived from the dictator game in healthy subjects(n = 12).Statistical parametric maps for the above mentioned contrast and percent signal change for the decision period derived from the dictator game in the (a) right dorsolateral prefrontal cortex (MNI: 54, 8, 28), and (b) left dorsolateral prefrontal cortex (MNI: -54, 8, 28). The regions of interest are circled in red. All statistical parametric maps are thresholded at p[FWE] < 0.05 for k > 20.● p < 0.05. Error bar represents S.E.M.

Mentions:
A subgroup of our study population (12/20) showed a tendency to treat previously unfair opponents in fair ways. Here, we concentrated our analysis on the right (MNI: 54, 8, 28) and left (MNI: -54, 8, 28) dorsolateral prefrontal cortex (DLPFC), because previous work has suggested that these regions are involved in controlling prepotent emotional responses. We detected a significant difference between the conditions ‘fair treatment of previously fair opponent’ and ‘unfair treatment of previously unfair opponent’ (paired-t11 = -2.653; pone-sided = 0.011) in the right DLPFC, whereby the activation in the latter condition was greater than in the former. Notably, subjects showed a significantly enhanced activation of the right DLPFC concerning the condition ‘fair treatment of previously unfair opponent’ compared to ‘fair treatment of previously fair opponent’ (paired-t11 = 1.853; pone-sided = 0.045). In the left DLPFC we observed an enhanced neuronal response regarding the condition ‘unfair treatment of previously unfair opponent’ compared to ‘fair treatment of previously fair opponent’ (paired-t11 = 1.979; pone-sided = 0.037), and compared to ‘fair treatment of previously unfair opponent’ (paired-t11 = 2.583; pone-sided = 0.013) (Figure 5).

Bottom Line:
Neuroimaging studies suggest that punishing unfairness is associated with the activation of a neural network comprising the anterior cingulate cortex, anterior insula, the ventral striatum, and the dorsolateral prefrontal cortex (DLPFC).A substantial number of subjects did not retaliate.Neurally, this "forgiveness" behaviour was associated with the activation of the right (and to a lesser degree left) DLPFC, a region that serves as a cognitive control region and thus may be involved in inhibiting emotional responses against unfairness.

ABSTRACTHumans have evolved strong preferences for equity and fairness. Neuroimaging studies suggest that punishing unfairness is associated with the activation of a neural network comprising the anterior cingulate cortex, anterior insula, the ventral striatum, and the dorsolateral prefrontal cortex (DLPFC). Here, we report the neuronal correlates of retribution and "forgiveness" in a scenario, in which individuals first acted as a recipient in an Ultimatum Game, and subsequently assumed the position of a proposer in a Dictator Game played against the same opponents as in the Ultimatum Game. Most subjects responded in a tit-for-tat fashion, which was accompanied by activation of the ventral striatum, corroborating previous findings that punishing unfair behaviour has a rewarding connotation. Subjects distinguished between the human opponent and computer condition by activation of the ventromedial PFC in the human condition, indicative of mentalising. A substantial number of subjects did not retaliate. Neurally, this "forgiveness" behaviour was associated with the activation of the right (and to a lesser degree left) DLPFC, a region that serves as a cognitive control region and thus may be involved in inhibiting emotional responses against unfairness.